Rename setups and add provider reauthentication

server/src/session/import.rs

@@ -13,7 +13,7 @@
 //!
 //! **The phone never names a file.** It picks an id out of what this
 //! module enumerated, and the path is looked up again on the server -- the
-//! same rule the setups model follows for providers, and for the same
+//! same rule the machines model follows for providers, and for the same
 //! reason: an enrolled token must not be able to turn into "read me this
 //! arbitrary path".